Portable machine for reboring engine-cylinders



R. :EIROSEBERRY. PORTABLEMACHINE FOR REBORING ENGINE CYLINDERS.

' APPLICATION FILED OCT. 23. 19!]. 1,315,580.

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PORTABLE MACHINE FOR REBORING ENGINE CYLINDERS.

APPLICATION FILED 0CT. 23. 19H- 1 ,3 1 5,580 Patenfed Sept. 9, 1919.

4 SHEETS-SHEET 2.

R. E. ROSEBERRY.

PORTABLE MACHINE FOR neeonma ENGINE CYLINDERS.

APPLICATION FILED OCT. 23. 19H.

1,315,580. Patented Sept. 9,1919.

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R. E. ROSEBERRY. PORTABLE MACHINE FOR REBORING ENGINE CYLINDERS.

APPLICATION FILED OCT- 23. I917.

Patented Sept. 9, 1919.

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ROBERT E. ROSEBERRY, 0F DETROIT, MICHIGAN.

PORTABLE MACHINE FOR REBORING ENGINE-CYLINDERS.

Specification of Letters Patent.

Patented Sept. 9, 1919.

Application filed October 23, 1917. Serial No. 198,160.

To all whom it may concern: 7

Be it known that 1, ROBERT E. RosEBERnY, a citizen of the United States, residin at Detroit, in the county of Wayne and tate of Michigan, have invented certain'new and useful Improvements in Portable Machines for Reboring Engine-Cylinders, of which the following is a specification.

My present invention relates to new and useful improvements in portable machines for re-boring engine cylinders and more particularly to that type of machine disclosed in a patent issued to me January 2, 1917, N0. 1,210,843, and in a copending application filed by me December 14., 1916, and bearing the Serial No. 137,018, the primary object of my invention being to so construct the machine that its eliiciency and accuracy will be increased while the time and labor necessary to its use will be decreased.

More specifically one of the primary objects of my invention consists in so simplifying the machine as to do away with a number of heretofore necessary adjustments when setting the machine up for use.

In this connection one of the objects of this invention is the provision of an improved form of body or housing which replaces certain separable part-s embodied in my, previous machines and which simplifies the manner of applying the machine to a cylinder block to be operated upon.

Another object of my invention consists in providing for more accurate supporting and centralizing of the feed screw and cutting mechanism which constitute the main working parts of the machine. 1

In my previous machines the sole bearing for the feed screw was through engagement of its threads with the threads of thefeed nut and as this thread has to be relatively fine to secure the desired slow feeding of the cutter head through thecylinder considerable trouble was experienced due to the wearing of the fine threads of the feed screw and its nut and due to likelihood of crossing of these threads when assembling the parts.

In this connection one of the principal objects ofmy present invention is the provision of a feedscrew having square threads so that the screw may be journaled in bear ings which will hold it against any undesired movement withou injury to the thread.

A still further object resides in providing a change speed gearing operating in connec wear and strain upon the individual thread i and all likelihood of crossing of the threads is avoided.

In my previous machines I provided an expansi-ble pilot ring which was pushed through the cylinder by the cutter head and in advance of the cutter head to assist in holding the cutter head in centralized position with respect to the bore being treated. Vith some types of cylinders, however,

when boring from the head to the crank 5 casing end of the cylinder the cylinder block is recessed at the ends of the cylinder for connecting rod. clearance and with cylinders of this type I have found that when approachlng the end of the bore the ilot ring would in some instances drop rom place and that as a result some slight jumping or undesired movement of the cutter head might occasionally occur.

One of the primary objects of this invention consists in providing a second pilot or centralizing ring which is also pushed through the cylinder by the cutter head, but which is located at the rear of the cutters and which consequently can not drop out of place until the cutter has passed completelythrough the cylinder. In this connection'a still further object of my invention is to construct these expansible rings with inner or upper beveled faces engaging against corresponding faces of the cutter head so that pressure of the cutter head forcing them through the cylinder. will act to force them into close engagement with the cylinder wall and to so proportion the bevels of these faces that the cutter ring at the rear of the cutter head will be forced into more firm engagement with the cylinder wall than the cutter ring in advance of the cutter head.

WVith these and other objects in view, my invention will be more fully described, illustrated in the accompanying drawings and then specifically pointed out in the claims which form a part of this application.

In the drawings:

Figure 1 is a perspective view of my 1111- proved machine showing it applled to a cylinder block;

Fig. 2 is a vertical central sectional view of the machine also taken centrally of the jack shaft forming part of the variable speed gearing employed;

Fig. 3 is a horizontal sectional v1ew taken on the line 3-3 of Fig. 2;

Fig. 4: is a partially unassembled perspective View of the cutter head and the pilot rings;

Fig. 5 is a diametric vertical sectional view taken through the cutter head and its pilot rings showing the parts assembled;

Fig. 6 is a transverse sectional view taken on the line 66 of Fig. 5 showing the disposition of the cutter blades;

Fig. 7 is a fragmentary perspeotlve view of the jack shaft also shown in Fig. 2, and a key cooperating therewith.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

My present machine primarily includes a supporting and centering casting or body, a cutter mechanism and a feed mechanism for operating the cutter. The supporting body is in the form of a cylindrical casting 10 provided at its lower end with diametrically extending flanges forming a supporting plate or base 11 the lower face of which is machined so that it may rest smoothly against the open end of a cylinder block 12. Brace webs 13 may be provided to reinforce the flanges 11 as will be readily understood by reference to Figs. 1 and 2 of the drawings. Each of the end portions of the supporting base 11 is formed with a pair of spaced parallel slots 14 through which cap screws 15 may be passed, these cap screws being threaded into the usual bolt openings always found in the ends of a cylinder block. Obviously, by this arrangement the body may be firmly clamped to the cylinder block and in axial alinement with the bore of the cylinder to be operated upon, the slots permitting such adj ustment as is necessary for this purpose. The body 10 is, of course, tubular in construction and should be of a diameter somewhat greater than the diameter of the bore of any cylinder upon which the machine is to be employed. For the sake of lightness and also to permit inspection of the work being done and ready access thereto the lower portion of the body may be formed with openings or hand holes 16, as best shown in Fig. 1.

This body at its upper end is formed with an annular seat 17 to seat the marginal portion of a cap plate 18 so that it will lie with its upper face flush with the upper edge of the body. The wall at the upper portion of the casting or body is interiorly thickened at spaced intervals to provide bosses 19 having internally threaded sockets open at their upper ends to receive cap screws 20 by which the cap plate or bonnet 18 is secured in place. This cap plate is formed centrally with a cylindrical opening or bore adapted to receive the feed screw, as will be later explained, and surrounding this opening or bore and extending above the cap plate is a sleeve which provides an elongated bearing 21 for the feed screw.

A partition wall 22 extends transversely of the body in spaced relation below the cap plate 18 and is formed with a bore and bearing sleeve 23 corresponding to the bearing 21 and in accurate alinement therewith.

J ournaled in these spaced bearings 21 and 23 is the feed screw 24. provided with a relatively coarse square thread, as shown in Fig. 2. This feed screw has threaded engagement with a combined feed nut and spur gear 25 which rests upon the partition wall 22. A washer 26 fits loosely about the feed screw and rests upon the combined nut and gear 25 and resting upon this washer is a spur gear 27 of slightly less diameter than the gear 25. The feed screw throughout its entire length is formed in one side with a longitudinal channel or keyway 28 which if desired need be of no greater depth than the depth of the thread, and the spur gear 27 is formed with an integral projection or key 29 fitting loosely in this keyway. It will therefore be apparent that while the feed screw is free for movement through the gear 27 such gear will always be driven when the feed screw is rotated.

A shaft 30 has one end journaled in a bearing 31 formed in the partition wall 22 and projects through the cap plate 18, to be journaled in a bushing 32 shrunk into the cap plate and securely held against movement therein. This shaft carries a spur pinion which is preferably formed integral with the shaft and also carries a loose pinion 34, these pinions meshing with the gears 25 and 27 respectlvely. The pinion 3 1 is formed with a key-seat 35 and the bushing 32 with a keyseat 36 adapted in one position of the pinion 31 to aline with and form a continuation of the seat It should be noted that this latter key-seat 36, however, does not open through the top of the bushing so that a stop shoulder is provided. The shaft 30 is formed with a keyway 37 extending from the level of the lower end of the keyseat 35 through the outer end of the shaft, and slid ably mounted in this keyway is a key slide- 38 provided at its lower end with a key proper, or extension 39 operating in the keyse-ats and v36 and capable of being dis posed, wholly in either one or the other of these seats. The upper end of the "slide, even when it is in its lowest position, projects above the shaft 80 and through a knob 40 which surrounds the extended end of the shaft, being fastened tomove with the knob, as indicated at 41. Obviously, with this arrangen'ient, by raising and lowering the knob the key 39 may be moved into the pocket 36 or the pocket 35 as the case may be. The shaft 30 at that portion inclosed within the knob 40 is formed with a diametric opening 42 leading into the keyway, and disposed within this opening is a detent forming ball 43 which is held against the rear face of the key slide 38 by a spring 44. The inner face of the slide 38 is formed at a suitable point with a seat 45 to receive this detent so that the knob and its key slide may be'frictionally held in elevated position with the key 39 in the key pocket 36 at such times as this positioning of the parts is desired. The upper end of the feed screw 24 1s squared'or otherwise formed with angular faces 46 to adapt it to receive a wrench or to permit its connection to a drill press while the lower end of the feed screw is formed with a re duced" externally threaded extension 47 and with an axial socket 48, this threaded extension and socket providing for attachment of the cutter mechanism as will be later explained.

The cutter mechanism of my machine consists primarily of a cutter head proper 49, an expander 50 for centering the cutters, a beveled head 51 for cooperation with the split expansible pilot ring 52, and the beveled head 53 for cooperation with the split expansible follower ring 54. The cutter head proper 49 is cylindrical in shape and 1s formed centrally and throughout its height with a threaded bore 54 and above the upper end of the bore with an annular collar or shoulder 55 internally threaded to form a continuation of the bore and provided with external angular faces 56for applicationof a wrench. The lower end of the cutter head proper is formed with radial slots 57 unifori'nly spaced from each other, six of these slots being provided to receive cutters or blades 58. These slots open at their inner ends into the bore of the cutter head and also into the bottom of the cutter head. The outer end of each cutter is formed with a cutting edge 61 which at its forward edge with respect to the direction of rotation of the cutter head is beveled or rounded rearwardly from such edge to suitably clear the freshly cut surface of the cylinder bore.

Tapped bores 62 are formed horizontally through the cutter head communicating with the slots and at right angles to the cutters to receive set screws 63 by which the. cutters are anchored against radial movement. The inner ends of the set screws arebeveledand centrally concaved to form annular cutting edges 64 in order that they may more firmly engage the cutters and the outer ends are formed with angular sockets 65 to receive a wrench.

The expander 50 includes a cylindrical externally threaded body 66 for threaded engagement within the bore of the cutter head and terminating at one end in a conical expanded head portion adapted to engage'the inner ends of the cutters which are beveled, as shown at 66, for this purpose. The ex pander, at its upper end, is provided with a relatively long shank having an angularly formed terminal 67 by means of which it may be turned to force the cutters outwardly to a greater or less extent. The free end of the conical portion and the free end of the shank are formed centrally with mandrel receiving sockets 68, as shown in dotted lines in Fig. 5, in order that the cutter mechanism as a whole may be mounted upon a lathe when the blades are being ground.

That portion of the cutter head above the blades or cutters is reduced to form a stop shoulder 69 and the upper portion of this reduced part is externally threaded, as shown at 70 for engagement with the beveled follower head 53 which is in the form of a sleeve interiorly threaded at its upper portion and smooth surfaced at its lower portion for proper locking engagement about the cutter head as best shown in Fig. 5. At this point it should be noted that the thread of the follower head and the thread 70 are left hand threads so that any friction against the follower head during turning and advancing movement of the cutter head through the cylinder bore will not cause loosening of the follower head. At the same time the engagement of the follower head against thestop shoulder 69 will prevent any undue tightening of the threads or strain thereon. The outer face of the follower is beveled inwardly and downwardly at an angle of preferably 70 to a point adjacent the top of the follower head to cooperate with the correspondingly formed inner face of the split expansible follower ring 54.

Cooperating with the above I described parts of the cutter mechanism is the beveled pilot head 51 which is in the form of a disk having its peripheral edge beveled inwardly and downwardly at an angle of substantially 60, as shownat 72, to engage against the correspondingly beveled inner face of the split expansible pilot ring 52. This disk is formed with a central bore 7 3 for accommodation of the expander and surrounding this bore is an annular centering collar 74 radially cut-away at intervals, as shown at 75, to snugly receive the cutters 58 when the beveled pilot head is applied to the cutter head, the uncut-away portions of the centering ring or collar seating in an annular recess 7 6 formed centrally of the lower face of the cutter head. It will, therefore, be apparent that this centering ring or shoulder seating in the recess of the cutter head serves to absolutely center the cutter head and pilot head with respect to each other while the cutters seating in the slots of the centering shoulder serve to lock the two heads against independent turning movement. The pilot head is formed with spaced bores 77 to receive cap bolts 7 8 which pass through them and have threaded engagement in correspondingly formed tapped bores 7 9 of the cutter head, the lower ends of the bores of the pilot head being counter bored to receive the slotted heads of the bolts 78 so that they will not project below the bottom of the cutter head assembly as a whole.

The cutter head in advance of each cutter has its lower edge notched, as shown at 80 in Fig. 4, to communicate with diagonally formed passages 81 in the beveled head to provide for the escape of shavings.

Unless my cylinder re-boring machine is intended for use with some particular size of engine cylinder alone a number of pilot heads of different sizes suitable for use in cylinders of different diameters and a corresponding number of follower heads of corresponding sizes are furnished with each machine. Of course, in any event a number of spring rings of slightly varying diameter for each pilot head and each follower head are provided.

When the machine is to be employed, cutters of suitable length for the cylinder to be operated upon are positioned in the cutter head and adjusted for the desired out by means of Vernier calipers or some other suitable instrument. A split follower ring of suitable dimensions is positioned about the cutter head, a follower head of suitable diameter is threaded upon the cutter head, and a pilot head of suitable size is secured to the cutter head. The cutter head is then threaded upon the lower end of the feed screw and when the feed screw is so disposed that the cutter head lies within the body 10, as shown in Fig. 2, the machine is placed upon the cylinder block directly over the cylinder to be rebored. A pilot ring is then interposed between the cylinder block and the pilot head and the cutter mechanism is lowered by means of the feed screw until the split pilot ring engages in the open end of the cylinder. The machine is then secured in this adjusted positionto the cylinder block by the bolts 15 so that no movement whatever is possible.

With the machine thus applied the knob 40 is depressed to occupy the position shown in Fig. 2 and lock the pinion 34 to the shaft 30 after which the feed screw is turned in a clockwise direction to rotate the cutter and feed it into the cylinder, this operation being continued until the cutter head has moved theentire length of the cylinder when the knob 40 is pulled to extended position to free the pinion 34 from the shaft 30 and the feed screw is counter rotated to free the cutter mechanism from the cylinder, after which the machine may be loosened and re moved.

With the pinion 3 f locked to the shaft 30 a slow feeding of the cutter mechanism is obtained due to the fact that turning of the feed screw drives the gear 27, because of the keyway and key connection between them this gear drives the pinion 34 and consequently the shaft 30 so that the pinion 33 drives the combined gear and feed nut 25 in the same direction as the feed screw but at a slightly slower rate of speed. Obviously with the feed nut 25 turning in the same direction as the feed screw but at a lower rate of speed the advance of the feed screw through the nut will be relatively slow. I have found that a convenient and efficient feed mechanism is one in which direct movement of the feed screw through its nut when the nut is stationary is at the rate of one inch to every six revolutions of the screw and in which the nut when driven moves at such speed relative to the feed screw as to cause advance of the feed screw through a distance of one inch for thirty-four revolutions of the feed screw. 7

With such an arrangement the cutter mechanism may be fed slowly and consequently with less effort, while the actual reboring is being done and may nevertheless be rapidly withdrawn after the boring operation is completed, a mere shifting of the knob 40 being all that is necessary to accomplish these results. Preferably the casing is formed with a radial groove or mark and the sleeve portion of the knob with a groove or mark which when brought into alinement with that of the casin will indicate that the key receiving pocket of the bushing 32 and the key receiving pocket of the pinion 34 are in alinement with each other so that the key may be shifted. This is possible due to the fact that the knob turns with the shaft 30. By the employment of this change speed gearing as part of the drive mechanism for the cutter it is possible to not only have the desired slow feed during active operation of the cutter and rapid feeding or retraction of the cutter after the boring operation is completed, but it is also possible to employ a feed screw having a relatively coarse square thread which Permits the provision of spaced bearings 21 and 23 for the feed screw. This is an important feature as these bearings prevent any undesired movement of the feed screw such as might result in the formation of an untrue bore in the cylinder.

.Furthermore, the pilot ring and follower ring both being forced into engagement with the cylinder wall, due to the beveled pilot and cutter heads pressing against them, provide guides or bearings both in advance and at the rear of the cutter which will prohibit any chattering of the cutter mechanism. With cylinders which at their crank case end have openings in their walls to provide clearance for connecting rods the pilot ring may at the latter part of the operation become displaced and fall out of position. Even though this occurs, however, the follower ring will maintain the cutter mechanism in proper axial alinement in the cylinder. Only a relatively light engagement between the pilot ring and cylinder wall is necessary and this is accomplished by having the beveled faces of the pilot head and ilot rin at an angle of sixt degrees. 11 the other hand a more bin ing engagement between the follower ring and cylinder wall is desirable and I accomplish this by beveling the faces of the follower ring and follower head at an angle of 70. Of course, these angles may be varied within suitable limits.

Furthermore, I have found that with cylinders having openings in their walls atthe crank case end if the cutter has only four blades the tool is apt to jump slightly as the blades pass the openings, while by the employment of a cutter head ha'ving six blades enough blades are constantly in engagement with the wall of the cylinder to prevent any such jumping.

Having thus described the invention, what is claimed as new is:

1. I11 an engine cylinder re-boring machine, a cutter head, cutters carried by the head, a beveled follower head fixed to the cutter head at the rear of the cutters with the face adjacent the cutters inclined inwardly, and an expanding follower ring engaging the beveled face of the follower head.

2. In an engine cylinder re-boring machine, a cutter head, cutters carried by the head, a beveled follower head fixed to the cutter head at the rear of the cutters with the face adjacent the cutters inclined inwardly, and an expanding follower ring engaging the beveled face of the follower head, the ring having a face beveled in conformance with the beveled face of the follower head nd engaging against such face.

3. In an engine cylinder re-boring machine, a cutter head, cutters carried by the.

head, a pilot head fixed to the cutter head in advance of the cutters, a follower head fixed to the cutter head at the rear of the cutters, and expanding pilot and follower rings en'- gaging their respective heads.

4. In an engine cylinder re-boring machine, a cutter head, cutters carried by the head, a pilot head'fixed to the cutter head in advance of the cutters, a follower head fixed to the cutter head at the rear of the cuttters, and expanding pilot and follower rings engaging their respective heads, the engagement between the heads and rings being such as to force the rings into engagement with a cylinder during feeding of the cutter head therethrough.

5. In an engine cylinder re-boringniachine, a cutter head, cutters carried by the head, a pilot head fixed to the-cutter head in advance of the cutters, a follower head fixed to the cutter head at the rear of the cutters, and expanding pilot and follower rings engaging their respective heads, the engagement between the heads and rings being such as to force the rings into engagement with a cylinder during feeding of the cutter head therethrough, the follower ring being forced into closer engagement than the pilot ring.

6. In an engine cylinder re boring machine, a cutter head, cutters carried by the head, a pilot head fixed to th forward face of the cutter head and having its lower face beveled at substantially an angle of 60, a split resilient pilot ring having its upper face beveled at the same angle engaging against the beveled face of the pilot head, a follower head having detachable engagement with the cutter head at the rear of the cutters and having its forward face beveled at an angle of substantially and a split resilient follower ring surrounding the follower head and having its rear face beveled for engagemenit against the beveled face of the follower hea 7. In an engine cylinder re-boring machine, a cutter head, cutters carried by the head, and expanding means carried by the head in advance and at the rear of the cutters to be forced into engagement with a cylinder wall through movement of the cutter head through the cylinder.

8. In an engine cylinder re-boring machine, a cutter head, cutters carried by the head through the cylinder, said means including expansible rings, and means coacting between the rings and head for causing their expansion.

9. In an engine cylinder reboring machine, a cutter head, cutters carried by the head, a pilot head fixed to the cutter head in advance of the cutters and provided with a beveled face, a follower head fixed to the cutter head at the rear of the cutters and provided with a beveled face, said face of the follower head being beveled at a greater angle than said face of the pilot head, and expanding pilot and follower rings engaging their respective heads.

10. In an engine cylinder reboring machine, a cutter head, cutters carried by the head, a pilot head fixed to the cutter head in advance of the cutters, a follower head threaded on the cutter head at the rear oi" the cutters, and expanding pilot and f0llower rings engaging their respective heads.

11. A cutting tool including a cutter head, cutters carried thereby, and expanding means carried by the head at the rear of the cutters for guiding and supporting the head with respect to the work.

12. A cutting tool including a cutter head, cutters carried thereby, and an expansible follower ring carried by the head at the rear of the cutters for guiding and supporting the head with respect to the work.

18. A cutting tool including a cutter head, cutters carried thereby, expanding means carried by the head at the rear of the cutters for guiding and supporting the head with respect to the work, and means coacting between said first mentioned means and the head for causing the expansion of said first mentioned means.

14. A cutting tool including a cutting head, cutters carried thereby, and expanding means respectively carried by the head at the front and rear of the cutters and adapted to coact for guiding and supporting the head with respect to the Work at opposite sides of the cutters.

In testimony whereof I affix my signature.

ROBERT E. ROSEBERRY. L 8.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Wuhlngton, D. G. 

